When you have anchors and articles with the same name, you get a disambiguation warning, and you can't make links.
You'll get a fixit for Insert '-anchor'and Insert '-article', but those just put -anchor or -article wherever your cursor is, which is kind of infuriating!
As far as I can tell:
It cannot be done. The existences of -anchor and -article are lies.
You have to name extra symbols differently, or DocC cannot cope. For example, if you want to link to an article named Concept, you will need to change your anchor like so: